cmd/update.sh: don't absorb ca-certificates installation failure
cmd/update.sh: don't absorb ca-certificates installation failure

nandub/brew,EricFromCanada/brew,MikeMcQuaid/brew,Homebrew/brew,nandub/brew,EricFromCanada/brew,nandub/brew,JCount/brew,Homebrew/brew,MikeMcQuaid/brew,JCount/brew,MikeMcQuaid/brew,EricFromCanada/brew,nandub/brew,Homebrew/brew,Homebrew/brew,JCount/brew,EricFromCanada/brew,JCount/brew,MikeMcQuaid/brew